When Tom Bergstrom paid $460,000 for his Portland riverside condo in July 2005, he expected it to be an urban escape from his home in Ashland.

But two days before Thanksgiving last year, Bergstrom and his wife, Martha Howard-Bullen, awoke to the pounding of construction above their McCormick Pier pied-à-terre on the west side of the Willamette.

Builders were installing a deck for the unsold unit atop their two-bedroom, 1,100-square-foot condo. Bergstrom, a 61-year-old retiree, says he asked for their building permit, but they didn't have one.

Nearly a year later, he's still struggling through a thicket of condo rules that involve the state, city, McCormick Pier's development company and its homeowner association.

For Multnomah County's growing condo set (filings for condo projects in the county show an increase from 51 in 2004 to 132 in 2005), Bergstrom's need to negotiate a crossfire of rules isn't uncommon.

For Portlanders who don't own upscale condos, these problems may prompt a shrug at best. But lawyers and building inspectors say condo disputes have been rising in Oregon for the past decade, with the worst perhaps yet to come. At the same time, Portland is betting on condos remaining an attractive option as it tries to build density in neighborhoods like South Waterfront.

Bergstrom successfully petitioned the city last December to issue a stop-work order on the deck above his unit. Inspectors then found five other decks built or being built without a permit in the 301-unit complex.

Shortly after work stopped, Bergstrom says rainwater began falling through the unfinished construction, flooding his condo and contaminating most of its drywall. In a letter last March to Bergstrom and his wife, developer Phil Carroll offered the couple "$10,000 for your inconvenience" and laid out a plan for a smaller deck to be built with water- and soundproofing. Bergstrom turned him down.

Carroll, who did not return messages seeking comment, started the process of making the decks legal with the city. But Bergstrom is challenging Carroll's right even to build those decks, arguing the association owns the condo complex, not Carroll.

When a condo project begins, the developer owns all the units and creates a homeowner association to manage common areas and pay for maintenance until at least 75 percent of the units are sold. After McCormick Pier passed that 75 percent point in February 2005, it held a "turnover" meeting in which homeowners took control of the board. But Carroll still sits on the board because he owns commercial units in the complex, such as the fitness center.

When Bergstrom went to the association in June challenging Carroll's right to build decks, the board backed Carroll's bid to bring the unpermitted decks into compliance.

Tom Morris, owner of an espresso bar at McCormick Pier as well as a residential unit there, says she sympathizes with both sides.

"Those units weren't selling very well, so he decided to put a deck up," Morris says of Carroll. "If I was the developer, I'd do the same thing.... I just hope everything gets settled quickly. I know the association has gone through hell with it."